Coil winder



y 1958 J. M. DREES ET AL 2,836,370

COIL WINDER 2 Sheets-Sheet 1 Filed Dec. 20, 1956 A T TOPNEY y 1 J. M. DREES ET AL 2,836,370

COIL WINDER 2 Sheets-Sheet 2 Filed Dec. 20, 1956 I N V EN T 055% M. [$52-53 KENNETH L. JONES ATTORNEY n 2,836,370 Ce Patented May 27, 1958 COIL WINDER Joseph M. Drees, Sunnyvale, and Kenneth L. Jones, Pacific Palisades, Calif., assignors to Sylvania Electric Products Inc., a corporation of Massachusetts Application December 20, 1956, Serial No. 629,608

8 Claims. (Cl. 242-9) This invention relates to coil winding apparatus, and more particularly is concerned with apparatus for winding very fine wire into coils or helices having an extreme- 1y precise spacing between turns.

In certain applications, for example in the fabrication of traveling wave tubes, it is necessary to employ coils or helices formed of extremely small wire, and for proper operation of the tube, it is essential that the spacing between turns be uniform to a high degree. It has been found, for example, that helices wound on gear-driven lathes, while apparently having uniform spacing between turns when examined by available precision gauging methods, did not provide satisfactory operation of the traveling wave tubes into which they were incorporated. The inoperativeness of the tube was due to the slight variation in the spacing between turns, imperceptible by the usual standards, cause-d it is believed, by the repetitive errors caused by the cyclic positioning of the gear teeth which are translated to the winding carriage.

It is an object of the present invention to provide apparatus for winding coils or helices having a precise and uniform turn-to-turn spacing.

Another object of the invention is to provide apparatus for winding coils or helices from wire of very small diameter and having uniform spacing between turns.

Another object of the invention is to provide apparatus of the class indicated in which the spacing between turns of the coil or helix is readily and conveniently adjustable.

Another object of the present invention is to provide apparatus for winding fragile coils or helices wherein the spacing between turns may vary in accordance with a predetermined function from one end of the coil ,to the other.

Still another object of the invention is to provide apparatus for winding multifilar coils or helices having a precise spacing between the turns of each coil and between the turns of one coil and the corresponding turn of the adjacent coil.

In the attainment of the foregoing objects, the apparatus contemplated by this invention employs a lathe for supporting and driving a coil winding mandrel in rotation, and on which a winding carriage is slidably mounted for movement parallel to the mandrel at a rate proportional to the angular velocity of the mandrel. The angular rotation of the mandrel is translated to a functionally related translational movement of the winding carriage through a system including a differential pulley and a series of wires or cables, thereby entirely eliminating the use of gears in the attainment of a suitable correlation between the angular velocity of the mandrel and the speed of travel of the winding carriage. Through the use of circular pulleys of different relative diameters, the pitch of coils having uniform turn-to-turn spacing can be readily changed, and should it be desired to have the spacing between turns vary from one end of the helix to the other in accordance with a predetermined function,

the function may be employed. The apparatus may also include a dividing head aflixed to the arbor which drives the winding mandrel to permit the winding of multifilar coils with uniform spacing between turns of each coil and between corresponding turns of adjacent coils.

Other objects, features and advantages of the invention will be apparent, and a better understanding of the construction and operation of a preferred form of the apparatus will be had from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. l is a front elevation view of a typical coil winder constructed in accordance with'the invention; 'Fig. 2 is a top plan view of the coil winder of Fig. 1;

Fig. 3 is an elevation cross-sectional view taken along line 33 of Fig. 2;

Fig. 4 is an elevation view, partially in section, taken along line 44 of Fig. 1;

Fig. 5 is an elevation view, partially in section, taken along line 55 of Fig. l; and

'Fig. 6 is an elevation view taken along line 66 of Fig.5.

Referring to the drawings, and more particularly to Figs. 1 and 2, the coil winding apparatus of the invention is preferably mounted on a structure similar to a lathe, having a suitably supported horizontally disposed bed 8 which, in turn, supports a horizontal plate 10. The plate 10 supports a bearing-support 16 at one end thereof, a bearing 34 for a precision spindle near the middle, and a somewhat conventional lathe tailstock at the other end. A lead screw 12, rotatably journalled at one end on support 16, is coupled at the other end, for example, by coupler 14, to one end of a spindle journalled in bearing 34, on'the other end of which is secured a chuck 30. The leadscrew 12, and consequently chuck 30, are driven in rotation by suitable driving means, such as an electric motor 24 supported on bed 8 and coupled to the lead screw by belt 20 passing over pulleys 18 and 22 respectively secured to an extension of the lead screw and the shaft of the motor. The helix or coil is wound on a mandrel 26, a small diameter rod, held at one end by chuck 30 and rotatable therewith, and supported at the other end by a chuck 28 freely rotatable on the tailstock. Thus, it is seen that motor 24 drives the lead screw 12, chuck 30-and mandrel 26 in rotation at the same angular velocity, about co-linear axes, there being no gears between the source of driving power and the mandrel. 7 An indexing head 32 is provided on chuck 30 and is arranged to rotate the chuck in discreet angular steps with respect to the lead screw 12 to permit the convenient winding of multifilar coils, as will be more fully explained hereinafter. The motor 24 is controlled by .a motorcontroller 36, conveniently positioned near the mandrel 26, the electrical connections between the controller and motor being entirely conventional and omitted from the drawing in the interest of clarity.

The rotational movement of lead screw 12 is converted to rectilinear motion of a carriage 38 which includes a lead screw nut 42 threaded on the screw 12 and constrained from rotation. In addition to the support afforded carriage 38 by the lead screw 12, it is slidably supported on bars 40 and 80, the ends of which are rigidly mounted on support 16 and the vertical supporting column for motor-controller 36. Thus, upon rotation'of lead screw 12, carriage 38 is smoothly driven along bars 40 and at a rate depending upon the angular velocity of the screw and in a direction depending upon the direction of rotation.

Referring to Figs. 3 and 4, lead screw nut 42 is threaded on lead screw 12 and is secured to carriage 38 through pivot members 94 and 96 to permit adjustment of the alignment between the axis of the lead screw and the direction of movement of the'carriage. The carriage is provided with bearings, shown generally at 98, to insure in substantially the same'horizontal plane with lead screw 12, and'is supported at its ends with its longitudinal axis parallel to lead screw 12.". .Rigidly secured to the carriage 38'by t'hfeaded stud 8'1, and projecting toward the front of theilathe bed (as viewed in Fig. 2) isa'quick-disconnect clamping member -8 2fac lapted to receive and clamp the carriage to a cable or wire50, the significance of which will appear herei nafte r. I

To summarize; the des'cription thus-far, motor24 drives lead screw rotation; which'in turn, through the action of lead'screw nut 42, "imparts translational movemerit to carriage '38 which is a linear function offthe V angularvelocityof lead screw 12 Motor24 also drives chuck 130; 'and hence mandrel 26, at the same angular velocity as the lead screw. Thus, there remain's tojdescribe thewiie-feeding carriage anam ans for imparting the translational movement of carriage38 to the wire feeding carriage so as to lay the wire from the feeding carriage ontothe mandrel with the desired spacing between turns. 7 Referring again to Figs; 1 and 2,:and to Figs. 5 and 6 for'd'etails'; winding carriage 44 is mounted on a horizontally disposed rod 46 for free movement therealong, the rod-146 being disposed parallel to the axis of mandrel 26 and rigidly supported at its opposite ends on the support for spindle' 34'and on the tailstock of the lathe, respectively; Carriage 44'is additionally supported on a bearing 45," which travels on horizontal plate '18. A bobbin 86-"of wire 81 of the type from which the coil ernsux is to be wound is mountedt on the carriage 44 'for rotation about an axis parallel to mandrel 26, the wire 87 bei'n'g fed fron i th'e bobbin over a wire guide 88,

seesaw A I idler pulleys 56 and 54, a counterweight 52 being 'suspended from the other end. The position of idlerpulleys 54 and 56 and the clamp-82 are adjustable to permit their being positioned in the same vertical plane as the selected groove of pulley 48 whereby carriage 38 may be attached to cable 50 without introducing transverse 7 strains in the cable in the flight between pulleys '54 t secured at one end to an anchor 70 in the outer'peripheral V groove of pulley48, passes over a portion of the circum- 'ference of the pulley, passesjover idler pulley 68, and

is anchored to horizontal plate 10 at 62, a weight 66 being supported on pulley 64 in th e loop in the cable between anchor 62 and pulley 68. 1

One endtof the third cable 72 is also anchored to pulley 48 at 58, is wrapped around a selected groove of pulley 48, passes under idler pulley 7-8,; which is V mounted on the lathe bed for free rotation about a horizontal axis, is wrapped around a second idler pulley 76, with a weight 74 suspended from the other free end'.' Pulleys 76 and 78-, and quick release clamp 84 are ad- V justable in a directiont-ransversely of the lathe b ed in formed of nylon, for xampu; and positioned as nearly secured to" thefcarriage and eitending toward the front enhance, su pe s; a Quick-disconnect clamp 3 4 for receiving and" en'gaging a wifef 72l' Translational move} ment 'of carriage 44-isfcontir6lledonly 'ther'moveim ent of 'the cable '72' a1ofig its; length W which will now be' described-"' t t 7 The heart ofthe driying means tor 'impflriting trans} lationalfmovenient to 'the wire feeding carriage asa predetermined 'function "of the trau slational movement of lead 'screw carriag38 isa difier tial pulley '48 mounted t on lath'e' bed 10' for tree 7 minim a hotizontal auis as'pfacticable t6 mandrel'26fto' ensufe that the Wire is Y eK 9 P= ii T?-Z 3 .11 5 t et n ntamel hese t ,e i al t s sm te c diff n im formed; on the conical surface to pr' ovidgin effect; a

plurality ofcoakial pulleys ct diflerentdiameters rotatable as a unit about acommon axis Alternatively, the pulley n'iir'ablysatisfactory), is secured at'oneend: tb aii ahchol' 8" 'n bi afia it pulley 48 nea is eter. ares P??? W a lu o e 9 la 'w hec we a s ngl lsj n l i s- F n i es i ns}; trength, or prefer-ab multiplestrand cable (the 'typefused inhir a d int rate 1Q,

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order that they may be positioned in the same vertical plane withthe selected gi oove'of pulley 48 over which i cable 72 passes. Clamp 84 is designed to engage cable 12 whereby carriage 44 is moved longitudinally along rod 46 in response to travel of cable 7-2along' its length;

With the cables 50, 60 and 72 laid ontpulley 48 :as illustrated, clockwise rotationoflead screw 12* (as viewed from the right-end in Fig; 1') drives lead screw carriage 38 from Vrightto left wherebycable 50 tends to pulley 48 inacounter-clockwise'direction (as viewed from p he. a r e 4 w l ra l in, a di ect o oppo i from th d t c Q t t vl l Qt, he sad c ewca ia e, n

bofh' t l i ea 5 3 111 how ca i s 35m f44i'w l agai a' i e Sa tdr z ct e t w tb'e j te het1e i as i 8 I d mr sht s le s a w sh 2 9 m n m ze i stiaa b t een lead screw 12 and nut 42 and to provide the torque P FQ Q for e mt l ept e f i J the t e i qn c Pulle 48; a longitudinal nt able 7 2 andweig'ht 66 is providedto permit convenient counterbalancitig Q entire system and provide, su ch tension as t'o obtain essentially frictionless'inovement of .carriagejt}, pulley548 andcarriage lfh VI In preparing'for thqwinding of a coil-or; helix, cables 59 and 72 are placeddin selected grooves in pull'ey48 (the selection being based on knowledge of the" pitch of lead screw 12 and the p s gmanni y introduced: by the m t" s oi the pulleys) to cause winding t faraterelative to the speedof carriage 44, to

rotationof mandrelv'26 tol lay on the desired number of fthe Up on starting motor 24 ,rotation of lead screw 12 drives carriage 38 from right to left, which in turn, through the action of cable 56, causes pulley 48 to rotate in a counterclockwise direction. This rotation of pulley 48 causes cable 72 to be wound onto the groove over which it passes causing wire-feeding carriage 44 to also move from right to left at a rate proportional to the speed of travel of carriage 38. With mandrel 26 being driven in rotation by chuck 30, the longitudinal movement of carriage 44- operates to lay a coil of wire onto mandrel 26 to form a helix having a predetermined pitch, or spacing etween turns. There being no gears between carriage 38 and carriage 44, the correlation between their movements is extremely accurate and variations in spacing between turns of the helix which might be caused by cyclical errors in gear trains are entirely eliminated. It has been found that coils may be wound on the described apparatus from wire having a diameter of the order of .0005 inch with a spacing between turns of as little as .0015 inch to a very high degree of accuracy, much superior than was heretofore attainable. When the carriage 44 has traversed the length of mandrel 26 a distance corresponding to the desired length of the coil, the motor is stopped,

the final turn of the coil is secured to the mandrel with an adhesive such as glue, cement, or the like, to prevent unwinding, the wire is cut, and the mandrel, with the coil thereon, is removed from the chuck 30 for further processing of the coil.

It will be apparent that so long as the peripheral grooves of pulley 48 over which cables 50, 60 and 72 pass are circular, the translational movement of carriage 44 will be in accordance with a linear function of the movement of carriage 38, and a uniform predetermined spacing between turns of the helix will result. Should a different spacing be desired, it is necessary only to select a different combination of pulleys to vary the linear function. in some applications, however, it may be desirable that the spacing between turns of the helix gradually vary from one end of the coil to the other in accordance with some function; e. g., very close spacing between turns at one end and a gradual increase in spacing toward the other end. Insofar as applicants are aware, a coil with these characteristics cannot be wound with suitable accuracy on existing coil winding machinery. With the present apparatus, such coils may be wound by merely replacing one of the circular pulleys of pulley 48, ordinarily the one over which cable 72 passes, with a cam-shaped pulley having a contour describing the desired function. With this modification, carriage 44 does not follow carriage 38 as a linear function, but instead, in accordance with a nonlinear function deterrnined by the shape of the cam, thereby introducing the desired variation in spacing between the turns of the coil, the mandrel 26, as before, being driven at the same uniform angular velocity as the lead screw.

The disclosed apparatus also conveniently lends itself to the winding of multifilar windings. After winding a single coil of uniform spacing between turns, or of varying spacing between turns, as just described, a second coil of like spacing but spaced slightly from the first, may be laid on the mandrel by turning dividing head 32 through a sub-multiple of a turn, for example a quarter turn, and repeating the winding process. In this connection, the machine has been found capable of winding a multifilar winding of 20 separate coils of .0005 inch diameter wire, with a spacing between corresponding turns of adjacent coils of .0015 inch with a high degree of accuracy.

Although the invention has been shown and described in terms of a specific preferred embodiment, applicants are aware that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the spirit of the following claims.

What is claimed is:

1. Winding apparatus for winding wire on a mandrel to form a coil or helix with a predetermined spacing between seesaw turns comprising, in combination, a lathe including a lead screw and a chuck for holding said mandrel, means for driving said lead screw and said chuck in rotation, a lead screw nut threaded on said lead screw arranged for longitudinal movement therealong in response to rotation of said screw, a wire-feeding carriage arranged for longitudinal movement along a path adjacent and parallel to the rotational axis of the mandrel, and means including a diiferential pulley and first and second cables passing over said pulley and respectively connected to said lead screw nut and to said carriage arranged to drive said carriage in response to and as a predetermined function of the movement of said lead screw nut.

2. Winding apparatus for winding wire on a mandrel to form a coil or helix with a predetermined spacing between turns comprising, in combination, a lathe including a lead screw and a chuck for holding said mandrel, means for driving said lead screw and said chuck in rotation about co-linear axes, a lead screw nut threaded on said lead screw arranged for longitudinal movement therealong in response to rotation of said screw, a wire-feeding carriage arranged for longitudinal movement along a path adjacent and parallel to the rotational axis of the mandrel, and means including a pulley having a plurality of peipheral grooves of different contours and first and second cables passing over selected ones of said grooves and respectively connected to said lead screw nut and to said carriage arranged to drive said carriage in response to and as a predetermined function of the movement of said lead screw nut.

3. Winding apparatus for winding wire on a mandrel to form a coil or helix with a predetermined spacing between turns comprising, in combination, a lathe including a lead screw and a chuck for holding said mandrel, means for driving said lead screw and said chuck in rotation at the same angular velocity about co-linear axes, a lead screw nut threaded on said lead. screw arranged for longitudinal movement therealong in response to rotation of said screw, a wire-feeding carriage arranged for longitudinal movement along a path adjacent and parallel to the rotational axis of the mandrel, a pulley having a plurality of peripheral grooves of difierent contours arranged for free rotation about an axis perpendicular to the axis of said lead screw, first and second cables passing over selected ones of said grooves and respectively connected to said lead screw nut and to said carriage arranged to drive said carriage in response to and as a predetermined function of the movement of said lead screw nut, and means connected to said cables for maintaining said cables in tension.

4. Coil winding apparatus for winding wire on a mandrel comprising, in combination, a rotatable chuck for holding said mandrel, a lead screw rotatable with said chuck, means for driving said lead screw and said chuck in rotation, a first carriage mounted on said lead screw and arranged for longitudinal movement therealong in response to rotation of said screw, a second carriage arranged for longitudinal movement along a path adjacent and parallel to the mandrel when held in said chuck, said second carriage including means for feeding wire onto said mandrel, a pulley having a plurality of peripheral grooves of difierent contours mounted for free rotation about an axis perpendicular to the axis of said lead screw, and a pair of cables respectively connected to said first and second carriages and each passing over one of said grooves for driving said second carriage at a predetermined rate relative to the rate of travel of said first carriage.

5. Coil winding apparatus for winding wire on a mandrel comprising, in combination, a lathe including a lead screw and a chuck for holding said mandrel, means for driving said lead screw and said chuck in rotation about co-linear axes at the same angular velocity, a first carriage including a lead screw nut mounted on said lead anew screw, a eebnd'earifor movement a1 n'gi aipat h', adjacent;

'29 a r 1 ,aai aidl ian lfrbii j a direction sl btamially normal to the axis of man- 435 new was bh' f l. er rl er s ace e.

different; nt g tre l' l at'el e 2am; @3 P r- Y5 Yf9 29tsd1 a id rst; and srqn r a s ach passingover one of said grooves for driving.

r toj the a s. of said lead screw, a pair of cables 7 screw: and. arranged for longitudinal. movement, there,

Held said c liuclc. V

,ae99 tdqa ia at ar detstm nad a e re a i s o, i

gal c ew: and; a. chuc ro atab eiwi hi s d lead, s ewfor i g said;mandrel rmeans'for driving said lead screw 3; said chuckinrotation; a lead screw nutth readed 'on said; lead; screw and; movable therealong in, responses to notation of said, screw at'a rate determined'by the. pitch andzangular velocityv of said screw, a wire-feeding. car.- ,7

riage arranged; for. movement along. a path. adjacent and parallel; towthe; mandrel when held by, said chuck including as bobbin. of wire and'means for laying wire onto said mandrel from a direction substantially normal to theiaxis. thereof, a pulley. having a plurality of peripheral grooves and freely rotatable. about an axis perpendicular tothe axis. ori'said lead screw, a first cable anchored at one end'toIsaid pulley and passingover a selected one of said grooves and attached to said lead screw nut, a second cable also anchored at one end to said pulley and passing" over a selected other one of said grooves and attached to said wire-feeding carriage, said pulley and saidcables being arranged to drive said wire-feeding carriage along said, path: in response to movement of said Ieadscrew nut, along said screw as a predetermined function of the'movement of said lead screw nut 7. Coil winding. apparatus for winding wire on a mandrel comprising, in combination, a lathe including a e WW- aai a a s 9. a l a .1 me ar rums; a 1 screw. and, said chuck 1n rotation about co-liriearaites lead scr ew nut fthreadedjon; said; lead screw and mo i therealongin response to rotati on of said screw a a I rate. determined by the pitch and angular velocity o f said screw, a, wire-feeding carriage arranged for movement along a ath adjacent and parallel to the mandrel; whenasklb a 1ii a r ac ns a bobbin Q e and means for; laying wire onto said mandrel from a; direction substantially normal to the axis thereof, a pulley;

having a plurality, of peripheral grooves arranged to be,

freely rotatableaboutan axis perpendicular to the a of; said lead screw, a first cable guided by means on said lathe; with a flight thereof substantially parallel to the axis of said lead screw and passing over aselectedone of said grooves and anchored atone end to said; pulley, means secured to the other end of: said first cablegyfori 'rnaintaining said first cable in tension,,m eans-securing said lead screw nut-to, said flight ofsaid first cable, a' second cable guided by means on said lathe withv a flight thereofglying along said: path and passing over ais elected other one. of said grooves and anchored at. one. end to. said pulley, means secured to the other'end of said second cable for maintaining said second cable intension, and means securing said wire-feeding carriage to said fiight-of'said second cable, said wire-feeding carriage being driven by said second cable in response to and as a predetermined function ofthe movement ofsaid-'- lead screw nutf 8; Apparatus in accordance with claim 4 and means includin ga third cable anchored'at oneend to saidpulley: for; controlling the relative tensions in i said first and second cables' i Refe en esfi edr h fi e o pr tant N TED ST ES PAT N otata e th. w- 

